A method for the production of coal water substance oils with improved storage stability of old

摘要

An additive for improving the ageing stability of hydrocarbon oils comprises a previously prepared mixture of at least one metal deactivator having the formula R-N=CY-NH-CY=N-R where R is a heterocyclic radical containing the group -C=N- in a 5 or 6 membered ring and Y is H or a cyclic or acyclic radical, or the two Y groups together with the =C-NH-C= form a cyclic structure with at least one antioxidant of the phenolic and/or amine type. Prefered metal deactivators are 1,3 di(21-pyridyl imino)iso - indoline, 2,5 di(21 - pyridyl imino)3,4 di-phenylpyrroline, 1,3 di(21-pyridyl imino)4,7 dithia 4,5,6,7-tetrahydro-isoindoline. Many examples of suitable phenol or amine antioxidants are given. The mixture may take the form of a solution of the metal deactivator in the antioxidant, mixed crystals of the two substances, or a concentrate of the two substances in a hydrocarbon oil.